I've only played with it so far and have not had a chance to really test it out. I'll do a full review once I can take it out for an extended session at night. Until then, I can say that it seems it would be an unfair advantage - it's just amazing how clear targets are in near darkness!

Then again, what is it that they say? If you find yourself in a fair fight, your tactics suck.

I bought a "cheap" Sightmark Ghost Hunter 2x24 1st Gen scope to try out in conjunction with an EOTech 552 on my PS90.

I haven't really had a chance to try it out with live fire yet, though. The first thing I noticed before I even turned it on was that if I wanted to use the artificial IR light attached to it, I would have to install some sort of shield to block the IR light from the holographic screen. By itself, the scope works great with the AIR in total darkness. But, behind the EOTech, it just completely washes out the holographic screen. By moonlight it works pretty well with the EOTech for a 1st Gen scope.

Actually, it isn't that the EOTech itself washes it out, but rather that the IR light reflects off the screen of the EOTech, so that all you can see is the reflected IR light through the scope.
Hmm. I might have to try swapping the order sometime and see if I can get a better result. I would definitely need the extended rail you have there, though, to fit them both on the rail.

Edit: Actually, even with an extended rail, I don't think it would work. The AA battery compartment on the front of the EOTech prevents the scope from sitting low enough to sit close enough to the EOTech.